Patent ID: 6930190

Claim:
A process for preparing heterocyclic pentalene derivatives having formula (I): wherein W is a sulfur atom, an oxygen atom or a NR or PR group wherein R is selected from the group consisting of a linear or branched saturated or unsaturated C 1 -C 20 -alkyl, C 3 -C 20 -cycloalkyl, C 6 -C 20 -aryl, C 7 -C 20 -alkylaryl and C 7 -C 20 -arylalkyl radical, optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements; R 1 , R 2 , R 3 and R 4 , equal to or different from each other, are hydrogen atoms or a linear or branched saturated or unsaturated C 1 -C 20 -alkyl, C 3 -C 20 -cycloalkyl, C 6 -C 20 -aryl, C 7 -C 20 -alkylaryl or C 7 -C 20 -arylalkyl radical, optionally containing heteroatoms belonging to groups 13-17 of the Periodic Table of the Elements; or R 1 and R 2 and/or R 3 and R 4 can form a C 4 -C 7 ring optionally containing O, S, N, P or Si atoms, said ring optionally bearing C 1 -C 20 alkyl substituents or being optionally fused with a C 4 -C 7 ring optionally containing O, S, N, P or Si atoms; said process comprising the following steps: a) contacting a compound of formula (II): wherein T is a OR, NR 2 , OH, CCl 3 , CF 3 , Cl, Br, I, imidazolyl or pirazolyl radical, with at least one molar equivalent of a vinyl compound of formula (III): wherein M is MgHal, Li K or ZnHal, and wherein Hal is chlorine, bromine or iodine, to form a compound of formula (IV): b) treating the compound of formula (IV) with a Brønsted acid to form a compound of formula (V): c) treating the compound of formula (V) with a reducing agent to form the correspondent alcohol of formula (VI): and d) dehydrating the alcohol of formula (VI).