A method for preparing a Precursor to Vitamin D Ring of the ring, a precursor of vitamin D, and Intermediate compounds

摘要

A method for preparing a precursor of ring a of the Vitamin D precursor having the formula (1), where a is a - CH2 - Group - CH2OH, ocor 'cor', 'CSR' 'or etinilo; R is Hydrogen or alkyl of C1 - 6; r1 is Hydrogen, alkyl C1 - 6 or a Group - (CH2) n OP; R2 is Hydrogen or a Group - R' op; C1 - 6 is alkyl or phenyl; R is Hydrogen, Hydroxy, alkoxy alkyl C1 - 6, 6 - Alquiltio C1, C1 - 6Or dialquilamino c1-3; p is Hydrogen; alcanoilo C1 - 6; in which the phenyl benzoyl is optionally substituted by alkyl c1-4, halogen or nitro; alcoxicarbonilo C1 - 6; if a group 3 (R3) where each R3 represents alkyl or phenyl independently C1 - 6; a mono - or di - alkoxy alkyl C1 C1 - 6 - 6; T Etrahidrofuranilo; or tetrahidropiranilo; n is 0, 1, 2, 3 or 4.A method comprising the steps of: (i) reacting a compound of formula (2) where a is alcoxicarbonilo C1 - 6 or dialquilamino carbonyl C1 3 and R is as defined above, with a vinilalcanoato Lipase or an acid anhydride; and (ii) convert the resulting Compound of formula (3) Or (4) where z is rent, rent preferably c1-3, corresponding to the compound of formula (1).A precursor of vitamin D ring, wherein the precursor has the formula (1) where a, r, R1 and R2 have the meanings given above, with the condition that the configuration of the compound (1) is 2S, 3rds, 4ths, is Formilo, Hydroxymethyl, etinilo or metoxicarb Onilo both R and R1 and R2 are Hydrogen, is not a Group - OSI (R3) 3.Intermediaries are also described for the preparation of precursor of formula (1).