Two important sandalwood chemicals, bacdanol and brahmanol, are sometimes used to replace santalol in a sandalwood formula. According to Arcadi Beau Camps, they “are olfactively related to the naturally occurring cis-B-santalol, but they are more powerful and more musky, lacking the outstanding floral character of the natural chemical.”
Polywood is used to “…enhance the macrocyclic musk and radiant products without imparting a specific character, but give volume and quality.”
Oxyoctaline formate is delicate, but has a particular floral radiance that makes it useful in any number of fine fragrances.
Okoumal is not as powerful as other woody chemicals, but it is soft and makes an excellent fixative.
Tobacarol is another of ABC’s favorites. He describes it as “…warm, woody and spicy, with notes of clove, mace and nutmeg, ambery, tobacco and others.” It works extremely well with citrus notes, in particular, lime. He describes its usefulness as a fixative and to provide body to a fragrance. He suggests a couple of accords, but most of what he calls for is unobtainable by ordinary mortals. Tobacoral can be used in fragrances up to 10%.
Hydroxyambran “…works extremely well with the limbanols, okoumal, and tobacarol. It provides body and fixation…”
Spirambrene resembles bois ambreine forte, orlimbanol, cedroxyde and cedramber. According to ABC, it imparts velvety nuances to woods.
Ebanol is a strong, distinctly sandalwood aroma that seems to enter into every sandalwood formula. ABC warns that it must be fresh or it develops off aromas.
ABC describes polysantol as one of the best sandalwood chemicals available. It apparently has a fruity nuance (hard for me to detect) that’s missing in sandalwood. He extols blends with firsantol because firsantol doesn’t have the fruity note and blocks it in the polysantol. He suggests an accord with ebanol, bacdanol, brahmanol, blue chamomile and sandela. He always includes sandela in his sandalwood accords because it is such a great fixative.
Firsantol is related to polysantol, but it’s dryer and doesn’t have the fruity note. ABC says it’s one of the best sandalwood chemicals around.
Koavone is less a sandalwood chemical than a floral-woody compound. It smells to me like methyl ionone and woods. ABC says it provides lift to top notes when methyl ionones or iso e super are used. I use it to provide a link between woods and florals.