Process for the manufacture of 3,4-dihydro-benzopyran derivatives and starting materials in this process
申请人:F. HOFFMANN-LA ROCHE & CO.
Aktiengesellschaft
公开号:EP0003221A2
公开(公告)日:1979-08-08
The invention is concerned with a novel process for the manufacture of chromane derivatives of the formula
wherein R, R1, R2 and R3 are hydrogen or lower alkyl and R4 is lower alkyl.
This process comprises reducing a compound of the formula
wherein R', R2 and R3 are hydrogen or lower alkyl and R',
R4 and R5 are lower alkyl, in a polar solvent in the presence of a base.
The invention is further concerned with the novel compounds of formula II which are used as starting materials.
The compounds of formula are, inter alia, valuable intermediates in the synthesis of vitamin E.
本发明涉及一种制造式中 R、R1、R2 和 R3 为氢或低级烷基,R4 为低级烷基的铬烷衍生物的新工艺。 该工艺包括在极性溶剂中,在碱存在下还原式中 R'、R2 和 R3 为氢或低级烷基,R'、R4 和 R5 为低级烷基的化合物。 本发明还涉及用作起始原料的新型式 II 化合物。 除其他外,式化合物是合成维生素 E 的重要中间体。