Synthesis of cyclic ketals
Abstract
Abstract CYCLIC KETALS ARE PRODUCED BY CONTACTING A DEHYDRATING AGENT WITH A COMPOUND OF THE FORMULA: HO-C(-R2)(-R3)-X1-R1-X2H WHEREIN X1 REPRESENTS OXY, THIO, OR NITRILO, WHEREIN X2 REPRESENTS OXY, THIO, OR IMINO, PROVIDED THAT AT LEAST ONE OF X1 AND X2 REPRESENTS OXY, WHEREIN R1 REPRESENTS AN ALKYLENE GROUP OF FROM 2 TO 4 CARBON ATOMS OR A 2BUTYLENE GROUP, AND WHEREIN R2 AND R3 INDIVIDUALLY REPRESENT HALOGENATED ALKYL GROUPS THE ALPHA CARBON ATOMS BEING FLUORO, CHLORO, OR BROMO. THE CYCLIC KETALS PROGROUP, THE REMAINDER OF THE HALO GROUPS ON THE ALKYL BEING FLUORO, CHLORO, OR BROMO. THE CYCLIC KETALS PRODUCED ARE REPRESENTED BY THE FORMULA: R2-C(-R3)<(-O-R4-X1-) WHEREIN X1, R2, AND R3 ARE AS DEFINED ABOVE, AND WHEREIN R4 REPRESENTS ALKYLENE OF 2 TO 4 CARBON ATOMS OR SUBSTITUTED ALKYLENE. THE DEHYDRATING AGENTS EMPLOYED INCLUDE CARBODIIMIDES AND ALPHA-AMINOACETYLENES. THE PROCCESS OF THE INVENTION IS USEFUL FOR THE PREPARATION OF 1,3DIOXOLANES, 1,3 - DIOXANES, 1,3 - DIOXEPANES, AND THEIR ANALOGUES WHEREIN ONE OF THE OXYGEN ATOMS IN THE HETEROCYCLIC RING IS REPLACED BY EITHER A SULFUR ATOM OR NITRILO GROUP.
Inventors
- 👤 S Delavarenne
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