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US 4,309,349 AGranted
Stereospecific process for preparing epoxybenzodioxans
AssigneeCiba-Geigy Corporation
InventorsHeinz W. Gschwend, Charles F. Huebner
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Abstract
The process depicted, for example, by the formulae ##STR1## yields valuable intermediates in the manufacture of drugs.
Claims9
A process for the stereospecific preparation of a compound of the formula ##STR11## wherein Ph is unsubstituted 1,2-phenylene or 1,2-phenylene substituted by one to three identical or different members selected from lower alkyl, hydroxy, lower alkoxy, lower alkylenedioxy, benzyloxy, lower alkanoyloxy, halogeno, trifluoromethyl or nitro;
- and R.sub.1 and R.sub.2 is hydrogen or lower alkyl;
- which comprises:
- (a) reacting a compound of formula II wherein ##STR12## Ph, R.sub.1, R.sub.2 have meaning defined above, R is CHO, one of Y and Z is R.sub.2 and the other is CH.sub.2 X wherein X is a halogen atom,
- with a compound R.sub.4 -OOH
- wherein R.sub.4 is hydrogen, lower alkanoyl, lower haloalkanoyl, HPhCO, HOOC-C.sub.2 H.sub.4 -CO, or HOOC-Ph-CO
- (b) cyclizing resulting compound III ##STR13## wherein R' is formyloxy and Ph, R.sub.1, Y and Z have meanings as defined in (a), with a base, being aqueous alkali, alkaline earth metal hydroxide or a strong quaternary nitrogen base.
3 more elements
A process for the stereospecific preparation of d,1-erythro-1,4-benzodioxan-2-yl-ethyleneglycol which comprises
- (a) reacting 2-(4-acetoxy-trans-2-butenyloxy)benzaldehyde with 3-chloroperbenzoic acid;
- and
- (b) treating the resulting 2-(4-acetoxy-trans-2,3-epoxybutyloxy)-phenyl formate with aqueous potassium hydroxide.
Dependencies are inferred from the claim text.