Intermediates and process for the preparation of sandalwood oil building blocks

A composition of matter consisting in an oxidized terpenes fraction (I) comprising:

• from 15 to 40% w/w of 3-((1S,2R,4R)-2-methyl-3-methylenebicyclo[2.2.1]heptan-2-yl)propanal, of formula
• wherein the bold and hatched line indicate an absolute configuration;
• from 1 to 8% w/w of 3-((1S,2S,4R)-2-methyl-3-methylenebicyclo[2.2.1]heptan-2-yl)propanal, of formula
• wherein the bold and hatched line indicate an absolute configuration;
• from 40 to 60% w/w of 3-((1S,3R,4S)-2,3-dimethyltricyclo[2.2.1.02,6]heptan-3-yl)propanal, of formula
• wherein the bold and hatched line indicate an absolute configuration;
• and
• from 5 to 20% w/w of 3-((1S,5S,6R)-2,6-dimethylbicyclo[3.1.1]hept-2-en-6-yl)propanal, of formula
• wherein the bold and hatched line indicate an absolute configuration;
• the w/w ratio being relative to the total weight of the oxidized terpenes fraction (I).