Abstract: A process for the preparation of diverse known and novel cannabinoids (5), which include cannabinol (CBN, 1), cannabinolic acid (CBNA, 2), cannabivarin (CBV, 3) and cannabivarinic acid (CBVA, 4) and other naturally occurring monocyclic and tricyclic cannabinoids and other analogues from simple inexpensive starting materials using a cascade sequence of allylic rearrangement, aromatization and, as appropriate, further highly selective cyclization reactions. Additionally, cannabinoids of the formula (5) and intermediates of the formula (9) form part of the invention. Use of medicaments comprising one or more of the disclosed cannabinoids alone or admixed with one or more other cannabinoids is also disclosed.

Abstract: Compounds of formula (I) ##STR1## in which R.sub.1 represents hydrogen, a C.sub.1-6 aliphatic hydrocarbyl group or a C.sub.1-4 aliphatic hydrocarbyl group substituted by a C.sub.3-6 alicyclic hydrocarbyl group or by a phenyl group, which phenyl group is unsubstituted or substituted by a halogeno or C.sub.1-3 halogenoalkyl group, R.sub.2 represents hydrogen, R.sub.3 represents hydrogen, a 5-or 6-membered ring aromatic heterocyclyl group containing one or two heteroatoms selected from nitrogen, oxygen and sulphur which is unsubstituted or substituted by a halogeno or C.sub.1-3 halogenoalkyl group, or a group AR wherein A is a straight chain C.sub.1-4 aliphatic hydrocarbyl group terminally substituted by R which is hydrogen, a phenyl group or a 5-or 6-membered ring aromatic heterocyclyl group containing one or two heteroatoms selected from nitrogen, oxygen and sulphur, which phenyl or heterocyclyl group R is unsubstituted or substituted by a halogeno or C.sub.1-3 halogenoalkyl group, R.sub.4 and R.sub.

Abstract: Compounds of formula (I) ##STR1## in which R.sub.1 represents hydrogen, a C.sub.1-6 aliphatic hydrocarbyl group or a C.sub.1-4 aliphatic hydrocarbyl group substituted by a C.sub.3-6 alicyclic hydrocarbyl group or by a phenyl group, which phenyl group is unsubstituted or substituted by a halogeno or C.sub.1-3 halogenoalkyl group, R.sub.2 represents hydrogen, R.sub.3 represents hydrogen, a 5- or 6-membered ring aromatic heterocyclyl group containing one or two heteroatoms selected from nitrogen, oxygen and sulphur which is unsubstituted or substituted by a halogeno or C.sub.1-3 halogenoalkyl group, or a group AR wherein A is a straight chain C.sub.1-4 aliphatic hydrocarbyl group terminally substituted by R which is hydrogen, a phenyl group or a 5- or 6-membered ring aromatic heterocyclyl group containing one or two heteroatoms selected from nitrogen, oxygen and sulphur, which phenyl or heterocyclyl group R is unsubstituted or substituted by a halogeno or C.sub.1-3 halogenoalkyl group, R.sub.4 and R.sub.

Abstract: An optical transducer system for producing an optical output signal representative of the rotational speed of a rotary member, particularly a shaft of a gas turbine engine, comprises a conventional inductive speed probe positioned adjacent the shaft to sense the passing of the teeth of a toothed wheel secured to and rotatable with the shaft. The inductive sensor thus produces an AC output signal whose frequency is proportional to the rotational speed of the shaft, and this signal is used to excite electrostatically vibration of a cantilever beam micromachined in silicon. The vibrating beam is arranged in an optical path defined by one or more optical fibres, such that its vibrations modulate light directed along the optical path at a frequency which is again proportional to the rotational speed of the shaft.