Calone or methylbenzodioxepinone, trade-named Calone 1951, also known in the industry as "watermelon ketone", was discovered by Pfizer in 1966. It is used to give the olfactory impression of a fresh seashore through the marine and ozone nuances. Calone is similar in structure to brown algae pheromones like ectocarpene and is also distantly related in structure to the benzodiazepine class of sedatives.^[1]

Calone

Names
Preferred IUPAC name 7-Methyl-2,4-dihydro-3H-1,5-benzodioxepin-3-one
Other names Calone 1951; Watermelon ketone; Methylbenzodioxepinone
Identifiers
CAS Number	28940-11-6 Y
3D model (JSmol)	Interactive image
ChemSpider	107218
ECHA InfoCard	100.044.823
PubChem CID	120101
UNII	0NQ136C313 Y
CompTox Dashboard (EPA)	DTXSID0047165
InChI InChI=1/C10H10O3/c1-7-2-3-9-10(4-7)13-6-8(11)5-12-9/h2-4H,5-6H2,1H3 Key: SWUIQEBPZIHZQS-UHFFFAOYAC
SMILES O=C1COc2c(OC1)cc(cc2)C
Properties
Chemical formula	C10H10O3
Molar mass	178.187 g·mol−1
Appearance	white crystals, flakes or clumps
Odor	distinctive
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	irritant
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Calone is an unusual chemical compound which has an intense "sea-breeze" note with slight floral and fruit overtones. It has been used as a scent component since the 1980s for its watery, fresh, ozone accords, and as a more dominant note in several perfumes of the marine trend, beginning in the 1990s. In 2014, Plummer et al. reported the synthesis and fragrance properties of several related aliphatic analogues. ^[2] Firmenich later releasing CASCALONE®, A sweet, watery version of CALONE® with a transparent floral signature^[3]