Abstract: A process for producing homoallyl alcohols of the general formula (I) ##STR1## in which either A.sup.1 or A.sup.3 represents a hydrogen atom, the other represents a single bonding along with A.sup.2 ; R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are the same or different and independently represents a hydrogen atom, or an alkyl or alkenyl group with or without being substituted with a hydroxyl group or an akoxyl group; and Y represents a hydrogen atom, an alkyl group or an alkenyl group, by reacting 1,3-glycols of the general formula (II) ##STR2## in which X and Y are the same or different and independently represents a hydrogen atom, an alkyl group or an alkenyl group, R.sup.1, R.sup.2, R.sup.3, R.sup.4, and R.sup.5 independently represents as defined above, at a temperature in the range of 130.degree. to 250.degree. C. in liquid phase with the contact of .gamma.-alumina catalyst.

Abstract: A process for producing isoprene in good yield is provided. The process is characterized in that an alkyl tertiary butyl ether and a formaldehyde source are fed, together with water, into a acidic aqueous solution continuously or intermittently while maintaining the reaction pressure in an adequate range and at the same time distilling off the product isoprene, unreacted starting materials, isobutene and tertiary butanol, together with water, from the reaction zone.

Abstract: A process for producing isoprene in good yield is provided. The process is characterized in that isobutene and/or tertiary butanol and a formaldehyde source are fed, together with water, into an acidic aqueous solution continuously or intermittently while maintaining the reaction pressure in an adequate range and at the same time distilling off the product isoprene and unreacted starting materials, together with water, from the reaction zone.

Abstract: Production of an alken-2-ol-1, or of an alken-2-ol-1 and an alkanol-1 from the corresponding alken-3-ol-1 is described. The above compound or compounds can be produced with good selectivity by converting an alken-3-ol-1 to the boric acid ester, and, then, contacting the ester with a palladium catalyst in the presence of hydrogen or, alternatively, by carrying out the latter-mentioned step under conditions favorable to the formation of said boric acid ester and, thereafter, subjecting the reaction product to solvolysis.