Preparation of 4-formyltetrahydropyrans, and novel 4-formyltetrahydropyrans

Abstract From the Canadian patent

25 - O.Z. 0050/38673, Abstract of the Disclosure: 4-Formyltetrahydropyrans of the general formula I, (I), where R1 is hydrogen C1-C12-alkyl, C2-C12-alkenyl, C1-C6-, alkoxy-substituted C1-C12-alkyl C4-C12-cycloalkyl, unsub-, stituted or substituted aryl hetaryl or aralkyl, or an, unsubsituted or substituted saturated or unsaturated 5-, membered or 6-membered ring which may be interrupted by N, O or S, are prepared by a process in which a pyran derivative of the general formula II, (II) where R1 is as defined above, R2 and R3 are each OH or together are an oxygen atom and thus form an oxirane ring and R4 is hydrogen where R2 and R3 are each OH and is, hydrogen or tert-butoxycarbonyl where R2 …