Bicyclic dioxanes, their preparation and their use as fragrant compounds

A compound of formula:

• wherein:
• R3 and R4 are independently a hydrogen atom, a C1-C6 alkyl group or a C2-C6 alkenyl group,
• R5 is selected from the group consisting of methyl, ethyl, i-butyl, t-butyl, n-pentyl, a C2-C6 alkenyl group and a (CH2)0-2-aryl group,
• R6 is a C1-C6 alkyl group, a C2-C6 alkenyl group, a (CH2)0-2-aryl group or a C5-C6 cycloalkyl or cycloalkenyl group, and
• R7 is a hydrogen atom, a C1-C6 alkyl group or a C2-C6 alkenyl group;
• or
• R3, R4 and R5 are as above defined, and
• R6 and R7 together with the carbon atom to which they are attached form a C5-C6 cycloalkyl or cycloalkenyl group;
• with the proviso that said compound is not:
• 2,2-dimethyl-4-ethylhexahydrobenzo[1,3]dioxine
• 2,2-dimethyl-4-n-penthylhexahydrobenzo[1,3]dioxine
• 2,2-dimethyl-4-phenylhexahydrobenzo[1,3]dioxine
• 2,4-dimethylhexahydrobenzo[1,3]dioxine
• 2,4-diphenylhexahydrobenzo[1,3]dioxine
• 4-ethyl-2-methylhexahydrobenzo[1,3]dioxine
• 4-methyl-2-phenylhexahydrobenzo[1,3]dioxine
• 2,2,4-trimethylhexahydrobenzo[1,3]dioxine.