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    44.
    发明专利
    未知

    公开(公告)号：DE3710805A1

    公开(公告)日：1988-10-20

    申请号：DE3710805

    申请日：1987-03-31

    Applicant: BASF AG

    Inventor： BECKER RAINER DR ,  ECKHARDT HEINZ DR ,  FISCHER ROLF DR ,  SPIEGLER WOLFGANG DR ,  VAGT UWE DR

    IPC: C07D309/08

    Abstract: A process for the preparation of esters of tetrahydropyran-4-carboxylic acid of the general formula I, where R1 is an alkyl, cycloalkyl, or aryl group, by treating butyrolactones of the general formula II, where R2 is a hydrogen atom, an alkyl group, or an acyl group -CO-R3, R3 being a hydrogen atom or an alkyl group with from 1 to 6 carbon atoms, with alcohols of the general formula III at temperatures of from 150 DEG C. to 400 DEG C. in the presence of acid catalysts.

    45.
    发明专利
    未知

    公开(公告)号：DE3628576A1

    公开(公告)日：1988-03-03

    申请号：DE3628576

    申请日：1986-08-22

    Applicant: BASF AG

    Inventor： SPIEGLER WOLFGANG DR ,  GOETZ NORBERT DR ,  SAUERWALD MANFRED DR ,  DOCKNER TONI DR ,  FISCHER ROLF DR

    IPC: C07D309/22 ,  C07D309/28 ,  C07D309/32

    Abstract: 3,4-dihydro-2H-pyrans I I where R1, R2, R3 and R4 are each H or C1-C6-alkyl and R3 is not C2-C4-alkyl when A is COOR5+L, and A is COOR5, =CHOR5, in which R5 is C1-C4-alkyl, or CH2OR6, in which R6 is C1-C4-alkyl or is benzyl which is unsubstituted or substituted by C1-C4-alkyl, alkoxy or halogen, or is formyl, C2-C4-alkylcarbonyl or benzoyl which is unsubstituted or substituted by C1-C4-alkyl, alkoxy or halogen, are prepared by eliminating an alcohol from a 2-alkoxytetrahydropyran II II where R7 is C1-C18-alkyl and A' is COOR5, CH(OR5)2 or CH2OR6, in which R5 and R6 have the meanings stated for I, the elimination being carried out by passing II, in the liquid or gaseous state, into a high boiling mineral oil at above the boiling point of the resulting dihydropyran I, removing I in gaseous form, replenishisng the high boiling mineral oil when it becomes enriched with byproducts, and removing the said mineral oil enriched with byproducts.

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