PREPARATION OF QUATERNARY PHOSPHORUS COMPOUNDS AND PHOSPHORUS YLIDES USEFUL AS INTERMEDIATES IN THE PREPARATION OF STEROLS

摘要

1514112 Quaternary phosphorus compounds and phosphorus ylides UPJOHN CO 2 Jan 1976 [27 Jan 1975] 33390/76 Divided out of 1514111 Heading C2P A betaine (III) of the formula wherein A is the portion of a Wittig reagent inert to the reaction medium and RSP1/SP, RSP2/SP and RSP3/SP are each H or methyl is obtained by reacting a methylene phosphorane: AP = CH 2 with an epoxide (IV) in an inert organic solvent. The betaine (III) may be converted to the corresponding ylide by contact with a strong base, e.g. sodamide, NaH or a lithium amide, expecially N-butyl lithium. The group AP may be the group X 3 P where each X is phenyl optionally substituted 1 to 3 times by a C 1 -C 4 alkyl group, or two X's are phenyl and the third is p-carboxyphenyl or each X is di(C 1 -C 3 alkyl)amino, and in this case the ylide has the formula where D is OM and M is the metal cation of a strong base. The betaine (III) in which AP is X 3 P may be converted to an ylide of Formula II wherein D is -OC(O)RSP4/SP and RSP4/SP is C 1 -C 6 alkyl, phenyl, benzyl or phenethyl, by reaction with an appropriate acylating agent containing the group RSP4/SP, e.g. an RSP4/SP acid anhydride or an RSP4/SP acyl halide, to form a quaternary ammonium compound and then reacting the latter with a strong base, e.g. lithium diisopropylamide to form the ylide in which D is -OC(O)RSP4/SP. Specified epoxides (IV) are ethylene oxide and isobutylene oxide.