Patent ID: 7465838

Claim:
A process for the preparation of C 2 -symmetric 1,4-diols of the formula IVA or IVB having a high enantiomeric purity wherein ring A which includes the shown double bond forms a mono-, di- or polycyclic aromatic or heteroaromatic ring and R 1 and R 2 are, independently of each other, an organic moiety, the process comprising reacting an α-(aryl or heteroaryl)-α-substituted alkanol compound of the formula IA (for the synthesis of a compound of the formula IVA) or IB (for the synthesis of a compound of the formula IVB) wherein ring A and R 1 are as defined under formula IVA and IVB, with a lithiating reagent, obtaining an intermediate of the formula IIA (from IA) or IIB (from IB), wherein ring A and R 1 have the meanings given under compounds of the formulae IVA and IVB, said process further comprising reacting the lithiated product of the formula IIA or IIB, respectively, with an N,N-di-alkyl-formamide to form a hemiacetal compound of the formula IIIA (from IIA) or IIIB (from IIB), wherein ring A, R 1 and R 2 have the meanings indicated for compounds of the formula IVA and IVB, and subsequently with a Grignard reagent of the formula R 2 MgX wherein R 2 is an organic moiety and X is halogen or, alternatively, using corresponding lithium, zinc or other metal comprising compounds that allow for introduction of R 2 ; to yield the corresponding compounds of formula IVA (from IIIA) and IVB (from IIIB).