Abstract: A single batch process for preparing (R)-benzyl-4-hydroxy-2-pentynoate by reacting (R)-3-butyn-2-ol with 1,1,1,3,3,3-hexamethyldisilazane to silylate the starting alcohol, followed by deprotonation with an alkyl lithium compound, then a reaction with a haloformate compound, and finally a hydrolysis reaction to arrive at the product ester.

Abstract: This invention provides a process for preparing the hypocholesterolemic compound comprising: (a) reacting p-fluorobenzoylbutyric acid with pivaloyl chloride and acylating the product with a chiral auxiliary to obtain a ketone of formula IV: (b) reducing the ketone of formula IV in the presence of a chiral catalyst to an alcohol: (c) reacting the chiral alcohol of step (b), an imine and a silyl protecting agent, then condensing the protected compounds to obtain a &bgr;-(substituted-amino)amide of formula VII: (d) cyclizing the &bgr;-(substituted-amino)amide of formula VII with a silylating agent and a fluoride ion catalyst to obtain a protected lactam of the formula VIII: and removing the protecting groups. The intermediates of formulas VII and VIII are also claimed.

Abstract: This invention provides an improved process for producing azetidinones. More particularly, this invention provides the steps of producing an trans-azetidinone represented by the formula ##STR1## from a carboxylic acid R.sup.2 --D--CH.sub.2 COOH, an aldehyde R.sup.1 --A--CHO and an amine RNH.sub.2, by the steps of: (a1) converting a carboxylic acid to the corresponding acid chloride; (b1) deprotonating a chiral oxazolidinone and treating the resulting anion with the product of step (a1); (c1) enolizing the product of step (b1) and condensing with the aldehyde; (d1) hydrolyzing the product of step (c1); (e1) condensing the product of step (d1) with the amine; and (f1) cyclizing the product of step (e1). Alternatively, the process comprises (a2) enolizing the product of step (b1) and condensing, in the presence of a Lewis acid, with a Schiff's base prepared from the aldehyde and the amine; and (b2) cyclizing the product of step (a2).

Abstract: Described is a process for the regioselective dehydration of 11-hydroxy steroids using PCl.sub.5, PCl.sub.3, POCl.sub.3 or either SO.sub.2 Cl.sub.2 and imidazole, or PPh.sub.3 and CCl.sub.4. The disclosed process selectively forms .DELTA..sup.9,11 steroids from either 11-.alpha.- or 11-.beta.-hydroxy steroids, and can also be used for the one-step conversion of 11,21 -dihydroxy steroids to 21-chloro-.DELTA..sup.9,11 steroids. Also disclosed are processes for the regioselective conversion of 11-.beta.-chloro steroids to .DELTA..sup.9,11 steroids, and for regioselectively converting an 11,17,21-trihydroxy streoid to a 21-chloro-11,17-dihydroxy steroid.

Abstract: Described is a process for the regioselective dehydration of 11-hydroxy steroids using PCl.sub.5, PCl.sub.3, POCl.sub.3 or either SO.sub.2 Cl.sub.2 and imidazole, or PPh.sub.3 and CCl.sub.4. The disclosed process selectively forms .DELTA..sup.9,11 steroids from either 11-.alpha.- or 11-.beta.-hydroxy steroids, and can also be used for the one-step conversion of 11,21-dihydroxy steroids to 21-chloro-.DELTA..sup.9,11 steroids.Also disclosed are processes for the regioselective conversion of 11-.beta.-chloro steroids to .DELTA..sup.9,11 steroids, and for regioselectively converting an 11,17,21-trihydroxy streoid to a 21-chloro-11,17-dihydroxy steroid.

Abstract: There is disclosed a novel formylating agent, 2-formylmercaptobenzothiazole.

Abstract: Described is a process for the regioselective dehydration of 11-hydroxy steroids using PCl.sub.5, PCl.sub.3, POCl.sub.3 or either SO.sub. Cl.sub.2 and imidazole, or PPh.sub.3 and CCl.sub.4. The disclosed process selectively forms .increment..sup.9,11 steroids from either 11-.alpha.- or 11-.beta.-hydroxy steroids, and can also be used for the one-step conversion of 11,21-dihydroxy steroids to 21-chloro-.increment..sup.9,11 steroids.

Abstract: An improved process for converting gentamicin B to isepamicin comprising forming 3,6'-di-N-formylgentamicin B, acylating the 1-amino group with an N-protected (S)-isoserine compound and removing all the blocking groups under conditions which result in high yields of isepamicin. A novel formylating agent, 2-formylmercaptobenzothiazole, and intermediate compounds are also disclosed.

Abstract: The preparation of arylethanolamines, and in particular albuterol (salbutamol), together with their novel boron, acetal and hemi-acetal intermediates is described.

Abstract: A high yielding process for converting 3,2',6'-tri-N-acetyl sisomicin to netilmicin comprising the step of silylating the starting material at the 5,2' positions, and optionally at the 4' position, converting the 1-amino substituent to a 1-N-imino substituent, converting the imino to an ethylamino, deprotecting the compound and recovering netilmicin. Also disclosed are novel intermediate compounds.