Abstract: The present invention relates to dihydropyran derivatives, processes for preparing, and processes of using the derivatives. The derivatives are prepared by condensation of lithium dienolate of prenal with an aldehyde or a ketone.The pyran derivative prepared from .beta.-ionylideneacetaldehyde when treated in the presence of a catalyst directly forms retinal.

Abstract: The (R) or (S) isomer of acetorphan or N-/2-acetylthiomethyl)-1-oxo-3-phenylpropyl/(S) alanine methyl ester is prepared by splitting of racemic acetylthio-2-benzylpropanoic acid by reaction with ephedrin, separation of the enantiomeric salt obtained, then freeing of the acid and coupling with the corresponding amino acid ester. The obtained preparations possess remarkable therapeutic activities and can notably be used as drugs.

Abstract: The present invention relates to dihydropyran derivatives, processes for preparing, and processes of using the derivatives. The derivatives are prepared by condensation of lithium dienolate of prenal with an aldehyde or a ketone.The pyran derivative prepared from .beta.-ionylideneacetaldehyde when treated in the presence of a catalyst directly forms retinal.

Abstract: The present invention relates to a process for preparing halo acetals of ethylenic aldehydes by reaction of a halogen cation with enamine followed by a hydrolysis and reaction with an alcohol, a glycol or an orthoformate. These halo acetals are used as intermediate for the synthesis of vitamins A and E.It also relates to a new compound of formula (IV), ##STR1## to a process for preparing it from halo acetals of ethylenic aldehydes by reaction with triethyl phosphate, and to its use for the preparation of retinal by reaction with .beta.-ionylideneacetaldehyde.

Abstract: The (R) or (S) isomer of acetorphan or N-12-acetylthiomethyl-1-oxo-3-phenyl propyl/(S) alanine methyl ester is prepared by splitting of racemic 3-acetylthio-2-benzyl propanoic acid by reaction with ephedrin, separation of the enantiomeric salt obtained, then freeing of the acid and coupling with the corresponding amino acid ester. The obtained preparations possess remarkable therapeutic activities and can notably be used as drugs.

Abstract: New intermediates and processes for the preparation of vitamins A and E, which are the acetals of 5,6-dihalo-3-methyl-3-hydroxyhexanal or of 6-halo-3-hydroxy-3-methyl-5-hexenal or 3-methyl-3-hydroxy-5-hexenal, as well as processes for making the intermediates. After dehydrohalogenation and dehydration these intermediates are condensed directly with .beta.-ionone or with 2-methyl-2-heptene-6-one to synthesize vitamins A and E respectively.

Abstract: A binary multiplier circuit has a logic operator acting as an exclusive-OR gate generating a first intermediate signal which is an exclusive-OR of a first input and a carry-in input. An inverter generates a second intermediate signal. A second logic operator generates a first output bit which is a symmetrical exclusive-OR of a second input and both the first and second intermediate signals. A second output bit is a symmetrical trigger function of the first and second input, depending on the first and second intermediate signals, and is generated in a transmission gate. Since the carry-in signal passed via the first and second intermediate signals is applied directly to transistors of the transmission gate, carry propagation delay is reduced. A fixed operand is multiplied by a variable operand by storing a partial result of the multiplication using an accumulator and a shift register with the binary calculation circuit.

Abstract: Process and device for the compression of image data by a mathematical transformation implemented at low cost, particularly for the transmission at reduced speed of sequences of images.The objective is to provide an economical method in "silicon area - processing speed" cost to implement a mathematical transformation of the DCT type, on arrays of pixels, suitable for image compression.According to the invention, the method consists essentially of combining a permutation (1) of each block of pixels with a series of one dimensional FFT (211, 213). A series of variants is obtained by adding or not adding steps of matrix calculation (22) of reconstitution of a complex 2D-FET, of rotations (3) of reconstitution of the DCT, and/or of suppression of the imaginary coefficients.

Abstract: A binary calculation circuit has a logic operator acting as an exclusive-OR gate generating a first intermediate signal which is an exclusive-OR of a first input and a carry-in input. An inverter generates a second intermediate signal. A second logic operator generates a first output bit which is a symmetrical exclusive-OR of a second input and both the first and second intermediate signals. A second output bit is a symmetrical trigger function of the first and second input, depending on the first and second intermediate signals, and is generated in a transmission gate. Since the carry-in signal passed via the first and second intermediate signals is applied directly to transistors of the transmission gate, carry propagation delay is reduced.

Abstract: The multiplier according to the invention comprises N shift registers (RD.sub.O, . . . , RD.sub.N-1) containing the words x.sub.i on B bits, N conditional adders (AdC.sub.O, . . . , AdC.sub.N-1) each adding to the partial sum which they receive a constant coefficient (a.sub.1), conditional on the value of the bit (x.sub.i,j) which they receive from the associated register (RD.sub.1) and an adder accumulator (AdAc). The digital filter using such a multiplier also comprises a parallel word input register.

Abstract: A circuit for performing binary calculation, the circuit being of the type having at least one cell possessing: a first bit input (Ai), a second bit input (Bi), a carry-in input (Ri-1), circuitry (1600) for generating a two input bit exclusive-OR signal (Ai.sym.Bi) and its complement (Ai.sym.Bi), circuitry (1800) for producing a result signal, and circuitry (1900) for producing a carry-out signal (Ri), the circuitry being constituted by multiplexed logic. The complemented two input bit exclusive-OR signal (Ai.sym.Bi) is produced by inverting the two input bit exclusive-OR signal (Ai.sym.Bi), thereby making it possible to utilize only 15 transistors in the most cut-down version of the circuit. The invention also relates to a circuit (20) having an addition cell (22) calculating the sum of the input bits and a subtraction cell (24) calculating the difference of the input bits. The circuitry (1600) for producing the two input bit exclusive-OR signal (Ai.sym.Bi) and its complement (Ai.sym.

Abstract: 6-halo-3-methyl-1-trialkylsilyloxy-1,3,5-hexatriene, useful as an intermediate in the preparation of terpene compounds, is prepared by reaction of a 6-halohexadienal with a halo-silane in the presence of a tertiary amine.

Abstract: 1,3,5-Nonatriene derivatives of formula: ##STR1## in which R.sub.1 and R.sub.2, together with the carbon atom to which they are linked, form a carbonyl group, or each of R.sub.1 and R.sub.2 denotes alkoxy or R.sub.1 and R.sub.2 together form an alkylenedioxy radical, which may be made by reaction of a butadiene derivative of formula: ##STR2## in which R is alkyl or phenyl, with a butanal ketoacetal of 10 formula: ##STR3## followed by reaction of the product with a halomethyltriphenylphosphonium halide, are useful intermediates e.g. for the production of phytol.

Abstract: Most of the useful discrete transforms of a signal X represented by N binary samples x0 . . . , xi . . . , x.sub.N-1 (Where N is a power of two) are such that, by combining the samples for obtaining the sum and the difference of couples of samples, the transforms may be converted into two transforms of half-length one of which may again be decomposed into two transforms of half-length. A device for computing such a discrete transform, for instance a discrete cosine transform (DCT) comprises a set of elementary circuits operating in serial arithmetic connected to receive the samples and arranged to provide the sums and differences of couples of the input samples on respective outputs; An additional circuit has inputs connected to the outputs of the elementary circuits for receiving the differences between couples of the input samples and for directly computing one of the two of the samples of the transform in distributed arithmetic.

Abstract: The device is applicable to data compression. It computes the discrete cosine transform X of a signal x represented by N digitized samples x, . . . x, . . . x, where N is a power of 2: ##EQU1## the device includes a convolver for convolution between the samples xi and a stored sequence of samples wi (N) and a set of identical elementary circuits grouped in serveral banks. Each circuit is a "butterfly" having two inputs and two outputs one of which delivers the sum and the other the difference of the two inputs. The elementary circuits of the first bank receive at their two inputs the samples of the convolution product whose indices are separated by N/2 from each other.

Abstract: Polyene aldehydes are made by reaction of a carbonyl compound of formula: ##STR1## in which R denotes a hydrocarbon radical and R' denotes hydrogen or alkyl, with a metal derivative of a halogen compound of formula: ##STR2## in which X denotes halogen (preferably bromine), R.sub.3 is alkyl, and either R.sub.1 denotes hydrogen and R.sub.2 denotes an alkoxy radical indentical with OR.sub.3 or R.sub.1 and R.sub.2 together form a bond, followed by hydrolysis of the product obtained.

Abstract: A multipler having two inputs and one output. Each input receives a binary input signal through a block which performs an arithmetic base change and encoding and a NTT circuit. The NTT is performed with a modulus M of the form 2.sup.P -2.sup.q +1. The output is applied to a block for decoding and return to the original arithmetic base in series relation with a NTT.sup.-1 circuit.

Abstract: Polyene aldehydes are made by reaction of a carbonyl compound of formula: ##STR1## in which R denotes a hydrocarbon radical and R' denotes hydrogen or alkyl, with a metal derivative of a halogen compound of formula: ##STR2## in which X denotes halogen (preferably bromine), R.sub.3 is alkyl, and either R.sub.1 denotes hydrogen and R.sub.2 denotes an alkoxy radical identical with OR.sub.3 or R.sub.1 and R.sub.2 together form a bond, followed by hydrolysis of the product obtained.